For airplanes of known type, the boat panel, positioned at the back of a landing gear and protecting the fuselage from debris and pebbles stirred up by the rolling of the tires during takeoff or landing, is made of aluminum and therefore has a coefficient of elongation to breaking, that is to say the rate of maximum elongation before breaking, of 9%. Because of the presence of frames with return at the aluminum skin, which are very rigid, when there is an impact between two frames, only the skin over a distance between the frames involved is acted upon and therefore the elongation over the panel is maximized, since the frames do not provide any latitude in radial deformation.
This metal panel is heavy, however, and therefore does not meet present-day needs to make airplanes lighter.